Various immersion thermocouples have been developed for repetitive measurements of molten metal baths during manufacture of steel or other metals. With repetitive thermocouples which may be immersed repeatedly within a short interval, the temperature of the expendable thermocouple assembly electrical connector between the expendable thermocouple and the immersion thermocouple can rise and the temperature can cause an EMF to be generated at the cold junction of the thermocouple wires and the electrical leads which connect the thermocouple to a recording unit. The EMF generated can provide non-representative test data or temperature data.